Generally, the driving assistance apparatus that assists in driving a vehicle acquires information of traffic conditions that require deceleration control of the vehicle, such as an intersection, stop sign position, curve, or approaching of a preceding car, by means of an on-vehicle camera or a navigation system. Driving assistance such as deceleration assistance is then provided through an audio braking guidance or a forced application of braking force based on the acquired information of traffic conditions around the vehicle.
The device described in Patent Document 1 has hitherto been known as one example of a driving assistance apparatus. The cruise control apparatus described in Patent Document 1 includes a cruise control means that executes inter-vehicle control when there is a preceding car in which it causes the host vehicle to follow the preceding car, and that executes speed control when there is no preceding car in which it causes the host vehicle to run at a constant speed. The cruise control apparatus also includes a collision determination means that determines an object that has a course intersecting the course of the host vehicle and may possibly collide with the vehicle. When the collision determination means detects an object that may possibly collide with the host vehicle, the degree of acceleration made by the cruise control means is reduced even if the cruise control means is executing the speed control as it detects no preceding car.
Namely, even if the cruise control means fails to recognize a vehicle ahead on the same lane as a preceding car due to an incorrect estimation of its course, the acceleration of the host vehicle is reduced based on the detection of an object with a collision potential by the collision determination means. Accordingly, the possibility of a situation that may give the driver a sense of discomfort, such as the host vehicle approaching the preceding car too closely, is reduced.